Arthroscopic Portals: Anatomy at Risk

Editorial Commentary: Shoulder Anatomy, Finding the Axillary Nerve: Measure Twice, Cut Once

Most descriptions of shoulder anatomy note that the axillary nerve lies approximately 5 cm below the anterolateral corner of the acromion, and the nerve has been reported to range from 2 to 7 cm from the acromial edge, depending on the patient and measuring technique. The safe trans-deltoid operable area has been described as up to 4 cm below the acromion. A useful clinical guide I use is that the inferior extent of the subacromial bursa ends above the axillary nerve.

In vivo biomechanical measurement and haptic simulation of portal placement procedure in shoulder arthroscopic surgery

A survey of 67 experienced orthopedic surgeons indicated that precise portal placement was the most important skill in arthroscopic surgery. However, none of the currently available virtual reality simulators include simulation / training in portal placement, including haptic feedback of the necessary puncture force. This study aimed to: (1) measure the in vivo force and stiffness during a portal placement procedure in an actual operating room and (2) implement active haptic simulation of a portal placement procedure using the measured in vivo data. We measured the force required for port placement and the stiffness of the joint capsule during portal placement procedures performed by an experienced arthroscopic surgeon. Based on the acquired mechanical property values, we developed a cable-driven active haptic simulator designed to train the portal placement skill and evaluated the validity of the simulated haptics. Ten patients diagnosed with rotator cuff tears were enrolled in this experiment. The maximum peak force and joint capsule stiffness during posterior portal placement procedures were 66.46 (±10.76N) and 2560.82(±252.92) N/m, respectively. We then designed an active haptic simulator using the acquired data. Our cable-driven mechanism structure had a friction force of 3.763 ± 0.341 N, less than 6% of the mean puncture force. Simulator performance was evaluated by comparing the target stiffness and force with the stiffness and force reproduced by the device. R-squared values were 0.998 for puncture force replication and 0.902 for stiffness replication, indicating that the in vivo data can be used to implement a realistic haptic simulator.

Effect of patient positioning in axillary nerve safety during arthroscopic inferior glenohumeral ligament plication

PURPOSE

To evaluate the risk of injuring the axillary nerve during an inferior glenohumeral ligament (IGHL) plication and finding out whether shoulder position (either beach chair position or lateral decubitus position) has any effect in this risk.

METHODS

The axillary nerve (AN) was identified through a 3-cm posterior incision in 12 cadaveric shoulders. Under arthroscopic visualization, a curved indirect suture-passing device was placed through the posterior and anterior bands of the IGHL. The distances between the device and the AN were measured with the shoulder specimen placed at simulated lateral decubitus position and beach chair position.

RESULTS

There were no cases of nerve injury nor the suture-passing device came closer than 10 mm to the nerve. There was an increase in the injury risk to the AN when inserting the device at the posterior band of the IGHL in the beach chair position [median 13 mm (range 10-21 mm)] compared to the risk in the lateral decubitus position [22.5 mm (20-26 mm), significant differences, p < 0.001]. When the device was inserted at the anterior band of the IGHL, there were no significant differences (n.s.) [lateral decubitus position: 18 mm (14-24 mm) vs. 16 mm (13-18 mm)]. When comparing differences between bands, there were no differences in the beach chair position, but the risk was lower for the posterior band in the lateral decubitus position (p < 0.001).

CONCLUSIONS

During plication of the posterior band of the IGHL, the risk is higher if the procedure is performed in the beach chair position. The posterior plication is safer than the anterior plication in lateral decubitus position.

CLINICAL RELEVANCE

This study helps the surgeon to better understand the proximity of the nerve to the IGHL and to highlight that the risk of nerve injury during capsular plication might be reduced in the lateral decubitus position.

Clinical Safety of the 5 O'clock Portal in Shoulder Arthroscopy: A Prospective Study

Background

The present study aimed to determine the rate of clinically significant neurovascular complications associated with the routine use of the 5 o'clock portal during arthroscopic Bankart repair.

Methods

Forty-eight consecutive patients underwent arthroscopic Bankart repair with the use of the 5 o'clock portal. These patients were followed at 2 weeks and 6 weeks postoperatively for subjective signs of neurovascular injury (i.e. numbness and tingling) as well as objective signs (i.e. intraoperative bleeding, radial pulse, capillary refill, sensation, motor strength, haematoma and oedema).

Results

Two out of 48 patients (4.2%) experienced transient neurological symptoms in an ulnar nerve distribution, which resolved by 6 weeks. There was no occurrence of clinically significant injury to the axillary nerve, axillary artery, musculocutaneous nerve, lateral cord of the brachial plexus or cephalic vein.

Conclusions

No clinically detectable neurovascular injuries were associated with the use of the 5 o'clock shoulder portal during Bankart repair.

Complications of arthroscopic shoulder surgery

Shoulder arthroscopic procedures have become common in today's orthopedic practice. The safety of shoulder arthroscopy though well established, is not without complications both minor and significant. The true incidence of complications is difficult to identify in the current literature. However, as with all procedures, complications associated with shoulder arthroscopy do occur. General complications (ie, infection), those specific to shoulder arthroscopy (ie, positioning) and those associated with specific procedures (ie, failure) all have been recognized. The purpose of this article is to review the current literature regarding complications in shoulder arthroscopy, provide insight into the risk factors and types of complications and to provide guidelines on the prevention and management of complications if and when they occur.

The arthroscopic "subdeltoid approach" to the anterior shoulder

Surgical management of shoulder pathologies has evolved tremendously during the past 3 decades, such that many lesions previously treated with open techniques are now addressed arthroscopically. Despite this movement, many surgeons and outcome studies continue to prefer open repairs as the gold standard, criticizing--with good reason--the reliability, reproducibility, and extended operative time of arthroscopic repairs, particularly with respect to anterior stabilizations and subscapularis repairs. With this in mind, we present the arthroscopic "subdeltoid approach," a novel standardized exposure technique for extracompartmental anterior shoulder arthroscopy. We define the subdeltoid space as the fascial plane bound superiorly by the acromion and coracoacromial ligament, medially by the coracoid and the conjoint tendon, inferiorly by the musculotendinous insertion of the pectoralis major to the humerus, and laterally by the lateral border of the humerus. When coupled with existing arthroscopic tools, this space dramatically enhances our ability to apply open techniques to some of the more challenging anterior shoulder pathoanatomy and expand the indications and efficacy of arthroscopy. This exposure technique has been used in more than 300 cases during the past decade to treat a myriad of shoulder pathologies, without any longstanding postoperative complications.

Iatrogenic suprascapular nerve injury after repair of type II SLAP lesion

Suprascapular neuropathy after an arthroscopic repair of a SLAP lesion is theoretically possible, but it has been rarely reported. We present a case of suprascapular nerve injury at the spinoglenoid notch as a complication of an improperly inserted suture anchor after repair of a type II SLAP lesion. The diagnosis was confirmed by the magnetic resonance imaging findings and an electrodiagnostic study, and direct compression of the nerve was visualized under repeat arthroscopy. An anatomic study of the superior glenoid shows that the available bone stock of the superior glenoid rim for the anchor insertion is found to decrease posteriorly. During the repair of a SLAP lesion, surgeons should consider the possibility of an iatrogenic injury to the suprascapular nerve by an improperly inserted suture anchor.

Complications in shoulder arthroscopy

Shoulder arthroscopy is generally a safe and effective method for treating a wide variety of shoulder pathology. Fortunately, complications following shoulder arthroscopy are rare, with reported rates between 4.6% and 10.6%.¹⁻⁷ These rates may be underestimated, as underreporting of complications and varying definitions of the term complication are likely. During shoulder arthroscopy, complications may occur at numerous points. The surgeon must be aware of potential problems and take necessary measures to prevent them. This article describes common complications after arthroscopic shoulder surgery. Although failure of treatment and postoperative stiffness are undesirable outcomes, they are not described.

A cadaveric analysis of the arthroscopic fixation of anterior and posterior SLAP lesions through a novel lateral transmuscular portal

PURPOSE

To compare the most commonly used portals with a novel, lateral transmuscular portal for the treatment of anterior and posterior SLAP lesions.

METHODS

Six paired cadaveric shoulders underwent arthroscopy to assess 3 different instrumentation portals: the anterior-superior lateral (AL) portal, the Neviaser (N) portal, and the Rothman-lateral (RL) transmuscular portal. After each portal was established, 5-mm cannulas were inserted followed by guidewire-assisted placement of implant fixation instruments. Each shoulder was then dissected to assess the relation of the instruments to the surrounding anatomic structures.

RESULTS

When the AL portal was used, instrumentation consistently passed through the rotator interval. When the N and RL portals were used, instrumentation penetrated the rotator cuff muscle belly at a mean distance of 25.75 and 7.67 mm, respectively, from the tendon. The mean angles of entry into the glenoid rim with respect to the glenoid articular surface were 32 degrees, 38 degrees, and -6 degrees for the AL, RL, and N portals, respectively. There was no violation of subchondral bone; however, 2 specimens showed weakened articular surfaces with use of the N portal. The RL portal was the only portal that allowed placement of instrumentation into all 3 zones of the superior glenoid rim (anterior superior, direct superior, and posterior superior) without violation of the subchondral bone and at the recommended 30 degrees to 45 degrees angle of entry.

CONCLUSIONS

The RL portal provides a safe and efficient method of arthroscopic fixation and knot tying of anterior and posterior SLAP lesions by use of a single instrumentation portal.

CLINICAL RELEVANCE

This novel, lateral transmuscular portal allows optimal angles of implant placement in all areas of the superior glenoid and provides a direct, simplified approach for arthroscopic knot tying.

Direct arthroscopy of the bicipital groove: a new approach to evaluation and treatment of bicipital groove and biceps tendon pathology

Assessment of the intra-articular and intertubercular regions of the long tendon of the biceps forms an important aspect of routine glenohumeral arthroscopic examination. We describe a new technique of direct visualization of the bicipital groove and tendon by positioning the arthroscope in linear alignment with the bicipital groove. A 4.5-mm cannula is introduced through a superior-medial (Neviaser) portal, into the glenohumeral joint, parallel and adjacent to the superior aspect of the biceps tendon, and is used as a viewing portal. The arm is then positioned in abduction, external rotation, and forward flexion, to align the groove with the arthroscope, thereby attempting to "look down the groove." The biceps tendon, as well as the structures forming its medial and lateral pulleys, can be evaluated from the glenohumeral and intertubercular aspects. A greater length of the medial and lateral lips and the floor and roof of the bicipital groove can be visualized by advancing the arthroscope deeper within the groove. A fat pad along the lateral wall of the groove serves as an anatomic landmark to limit dissection in this region, thereby preventing damage to the anterolateral ascending branch of the anterior circumflex artery. An extension of this technique, to facilitate instrumentation for arthroscopic biceps tenodesis, is described.

Arthroscopic perspective of the axillary nerve in relation to the glenoid and arm position: a cadaveric study

PURPOSE

The purposes of this study were to examine the morphologic features of the axillary nerve and its relation to the glenoid under an arthroscopic setup, and to determine the changes in nerve position according to different arm positions.

METHODS

Twenty-three fresh-frozen fore-quarter cadaveric shoulder specimens were used for evaluations in an arthroscopic setup with the lateral decubitus position. The main trunk of the axillary nerve with or without some of its branches was exposed after careful arthroscopic dissection. Morphologic features and the course of the axillary nerve from the anterior and posterior portals were documented. The closest distances from the glenoid rim were measured with a probe by use of a distance range system. The changes in nerve position were determined in 4 different arm positions. At the end of arthroscopic examination, the nerves were marked and verified by open dissections.

RESULTS

The axillary nerve appeared in the joint near the inferior edge of the subscapularis muscle. With reference to the inferior glenoid rim horizontally, the nerve had a mean running angle of 23 degrees (range, 14 degrees to 41 degrees; SD, 8 degrees ). The closest points from the glenoid were between the 5:30- and 6:00-o'clock position (right) or 6:00- and 6:30-o'clock position (left). The closest distance range varied from 10 to 25 mm in the neutral arm position. The abduction-neutral position resulted in the greatest distance between the inferior glenoid and the nerve.

CONCLUSIONS

The abduction-neutral rotation position was the optimal position for minimizing axillary nerve injuries, because it resulted in the greatest distance between the inferior glenoid and the nerve.

CLINICAL RELEVANCE

Knowledge of the anatomy of the axillary nerve aids the shoulder surgeon in avoiding nerve injury during arthroscopic procedures. Abduction-neutral rotation may be more helpful for arthroscopic surgeons performing procedures in the anteroinferior glenoid with the nerve being farther away from the working field.

The axillary pouch portal: a new posterior portal for visualization and instrumentation in the inferior glenohumeral recess

Arthroscopic access to the inferior glenohumeral recess is necessary in several surgical procedures on the shoulder. Posteroinferior portals described for access to this region may pose a theoretic risk to the posterior neurovascular structures (outside-in technique) and to the articular cartilage (inside-out technique). The first author (D.N.B.) has devised a new posterior portal that permits direct linear access to the entire inferior glenohumeral recess. The portal is placed higher and more lateral compared with the previously described portals; this places it further away from the posterior neurovascular structures and facilitates linear access to the axillary pouch. The portal is created via an outside-inside technique, with a spinal needle to ascertain the correct portal site and angulation. The portal is placed at a mean distance of 20.45 +/- 4.9 mm (range, 15 to 35 mm) directly inferior to the lower border of the posterolateral acromial angle and 21.3 +/- 2 mm (range, 20 to 25 mm) lateral to the posterior viewing portal. The spinal needle or cannula is angulated medially at a mean of 30.6 degrees +/- 4.7 degrees (range, 25 degrees to 40 degrees ) in the axial plane and slightly inferiorly (mean, 2 degrees ; range, 20 degrees superiorly to 20 degrees inferiorly). Use of 30 degrees and 70 degrees arthroscopes through the axillary pouch portal facilitates visualization of the entire recess and of the humeral attachment of the inferior glenohumeral ligament complex for evaluation of humeral avulsion of the glenohumeral ligament lesions. The portal also permits instrumentation in combination with the standard posterior or anterosuperior viewing portal for removal of loose bodies, synovectomy, capsular shrinkage, capsulotomy, and anchor placement in the posteroinferior glenoid rim.

The anatomy and function of the low posterolateral portal in addressing posterior labral pathology

PURPOSE

A standard posterior portal allows excellent visualization of the glenohumeral joint but is inadequate for anchor placement because of its parallelism to the glenoid surface. The purpose of this study was to describe the low posterolateral portal for glenohumeral arthroscopy, describe the anatomy of the portal and surrounding structures, and discuss the portal's usefulness in addressing posterior and inferior shoulder pathology.

METHODS

Five cadaveric shoulders were dissected after placement of a spear through the low posterolateral portal. The location was identified via a spinal needle, 2 to 4 cm lateral and 4 to 5 cm inferior to the posterolateral corner of the acromion. Measurements from the spear to the anatomic structures were recorded with a caliper. Seventeen patients with posterior labral pathology were included in this study. The low posterolateral portal was established while visualizing through the anterosuperolateral or posterior portal. The spear and anchor were inserted through the low posterolateral portal.

RESULTS

Five shoulders were dissected, and the neurovascular structures relative to the low posterolateral portal were identified. The portal was 13.8 +/- 1.6 mm from the axillary nerve and 13.4 +/- 1.2 mm from the posterior humeral circumflex artery. In the retrospective review the low posterolateral portal was created without difficulty or complication in all 17 patients. The portal was extremely helpful for anchor insertion in the posteroinferior glenoid. It was useful in suture passage through the posterior and inferior labrum and in suture management.

CONCLUSIONS

The low posterolateral portal provides the optimal angle for insertion of instruments and anchors, resulting in a more anatomic repair.

CLINICAL RELEVANCE

The standard 3 portals are not optimal for approaching posterior and inferior labral tears, and use of the low posterolateral portal improves access and treatment.

Anatomic risks of shoulder arthroscopy portals: anatomic cadaveric study of 12 portals

PURPOSE

The purpose of this anatomic cadaveric study was to determine with trocars in situ the relationships of 12 shoulder arthroscopic portals frequently used with the adjacent musculotendinous and neurovascular structures.

METHODS

Twelve shoulders of embalmed cadavers installed in a beach-chair position were dissected. Twelve different portals were established by using their authors' description: posterior "soft point," central posterior, anterior central, anterior inferior, anterior superior, 5 o'clock portal, Neviaser, superolateral, transrotator cuff approach, Port of Wilmington, anterolateral, and posterolateral. Six of these portals were placed on each shoulder so that each portal was studied 6 times. Dissections were conduced with trocars in situ to take into account their volume. The distance to the adjacent relevant neurovascular structures at risk (axillar and suprascapular nerves, axillar and suprascapular arteries, and cephalic vein) were measured, arm at side, by using a calliper. Musculotendinous structures crossed by portals were noticed.

RESULTS

The cephalic vein was injured twice by anterior portals. The 5 o'clock portal is at most risk of neurovascular injury. It is located at mean distances to the axillar artery and nerve of 13 and 15 mm, respectively. Other anterior, posterior, superior, and lateral portals are safe with mean distances higher than 20 mm. No musculotendinous rupture nor large injury occurred.

CONCLUSIONS

The present study shows that the trocars placement of the studied portals did not create, except for the cephalic vein, any lesion of the neurovascular adjacent structures.

CLINICAL RELEVANCE

This study suggests, except for the 5 o'clock portal, the safety of the shoulder arthroscopic portals tested regarding to the neurovascular adjacent structures.

The superior-medial shoulder arthroscopy portal is safe

PURPOSE

The superior-medial (SM) shoulder arthroscopic portal (Neviaser portal) is the portal anatomically closest to the suprascapular nerve, and any potential benefits of this portal would be mitigated if risk of suprascapular nerve injury were significant. The purpose of this study is to determine the safety of the SM arthroscopic shoulder portal. We hypothesize that the SM shoulder arthroscopic portal is safe.

METHODS

Twelve fresh cadaveric shoulders were securely positioned to simulate shoulder arthroscopy in the beach-chair position with the arm at the patient's side in neutral rotation. An SM portal was established 1 cm medial to the acromion and 1 cm posterior to the clavicle, and a 5.5-mm burr sheath was oriented toward the acromioclavicular joint. The skin and trapezius were resected, the supraspinatus was retracted, and the suprascapular nerve was identified. The distance between the sheath and the nerve was measured by 2 independent observers with calipers. A safe distance was defined as 10 mm.

RESULTS

The measured distances between the nerve and burr ranged from 18.5 to 35.7 mm, with a mean of 24.2 +/- 5 mm. The distance is significantly greater than the safe distance of 10 mm (P < .0001).

CONCLUSIONS

This study shows that the SM portal is safe. The distance between an instrument oriented toward the acromioclavicular joint via the SM portal and the suprascapular nerve was 18.5 mm or greater in all specimens.

CLINICAL RELEVANCE

Our study has clinical relevance because the SM portal is useful for arthroscopic rotator cuff repair, arthroscopic superior labrum repair, and arthroscopic distal clavicle excision.

Glenohumeral arthroscopy portals established using an outside-in technique: neurovascular anatomy at risk

PURPOSE

The purpose of this study was to examine the neurovascular structures at risk during placement of glenohumeral arthroscopy portals using an outside-in technique.

TYPE OF STUDY

Anatomic cadaveric study.

METHODS

Five fresh-frozen cadaveric specimens were used in this study. Each shoulder was mounted on a custom-designed apparatus allowing shoulder arthroscopy in a lateral decubitus position. The following portals were established using an outside-in technique and marked using an 18-gauge spinal needle: posterior, posterolateral, anterior, 5-o'clock, anterosuperolateral, and Port of Wilmington. Each specimen was carefully dissected after the procedure, and the distance from each portal site to the adjacent relevant neurovascular structures (axillary nerve, musculocutaneous nerve, lateral cord of the brachial plexus, cephalic vein, and axillary artery) was measured using a precision caliper.

RESULTS

Except for the cephalic vein, all of the neurovascular structures were more than 20 mm away from all the portals evaluated. When creating either an anterior portal or a 5-o'clock position portal, the mean distance from the portal to the cephalic vein was 18.8 mm and 9.8 mm, respectively. In one anterior portal, a direct injury to the cephalic vein occurred.

CONCLUSIONS

Our study suggests that shoulder arthroscopy portals placed in an outside-in fashion are unlikely to produce neurologic injury. However, the cephalic vein is at risk during placement of an anterior or 5-o'clock position portal, although probably with minimal subsequent patient morbidity. Placing portals in an outside-in fashion guarantees the correct angle of approach, with minimal risk to adjacent neurologic structures.

CLINICAL RELEVANCE

This study shows the safety of standard and accessory glenohumeral arthroscopy portals.

Temperature along the axillary nerve during radiofrequency-induced thermal capsular shrinkage

BACKGROUND

There have been reports of axillary nerve palsy after thermal capsular shrinkage with radiofrequency energy-generating devices. The exact cause of this is unknown.

HYPOTHESIS

The temperature of the axillary nerve increases during shoulder capsular shrinkage at various degrees of shoulder abduction.

STUDY DESIGN

Laboratory study.

METHODS

Fifteen cadaveric shoulders had fiberoptic thermometer probes placed at various points along the axillary nerve and major branches under the capsule. The shoulders underwent thermal capsular shrinkage with a radiofrequency energy-inducing device at various positions of abduction.

RESULTS

With the arm at the side, temperatures above 50 degrees C (56 degrees -61 degrees C) were evident along the teres minor branch of the axillary nerve in 4 of 6 specimens. The increase in temperature was noted in the middle to posterior aspect of the inferior capsule. At 45 degrees of abduction, 4 of 5 shoulders demonstrated increases in temperature greater or equal to 50 degrees. Three of 4 shoulders tested at 90 degrees of abduction revealed similar temperature increases.

CONCLUSIONS

The arthroscopic technique of thermal capsular shrinkage causes an increase in the temperature of the axillary nerve and its branches in 11 of 15 cadaveric specimens tested at various arm positions-particularly affected is the teres minor branch.

CLINICAL RELEVANCE

Orthopaedic surgeons using the radiofrequency device for thermal capsular shrinkage need to be aware of the possible increase in temperature along the axillary nerve and its branches during this procedure. The clinical effect of this type of increase on the nerve is unknown.

The new subclavian portal and modified Neviaser portal for arthroscopic rotator cuff repair

Shoulder arthroscopy and the introduction of suture anchors has provided the surgeon with the ability to repair rotator cuff tears through minimal incisions. Rotator cuff repair involves the use of several portals, such as the posterior portal, the anterior portal, the anterior superior portal, the anterior inferior portal, and the Neviaser portal. The authors have developed 2 additional portals, the new Subclavian portal and the modified Neviaser portal, to improve the safety and efficacy of rotator cuff repair and solve a number of problems associated with traditional repair techniques. The subclavian portal is located directly below the clavicle, 1 to 2 cm from the acromioclavicular joint, and instruments are aimed medial to lateral. The modified Neviaser portal changes the angle of insertion of the Neviaser portal. Instruments are aimed 20 degrees from the horizontal plane and 45 degrees anterior, directly at the suture anchor. Repair techniques using each portal were reviewed. Twenty cadaveric shoulders were dissected for each portal and the anatomy from each portal was documented. The cadaveric dissections showed that this portal passes greater than 6 cm from the brachial plexus, musculocutaneous nerve, and subclavian artery and vein, and 4.7 cm from the cephalic vein. The modified Neviaser portal was shown to be safer than the Neviaser portal because it passes on top of the supraspinatous muscle, thereby protecting the suprascapular nerve. These portals provide an optimal angle of approach to the rotator cuff tendon and suture anchor as well as improved safety and efficacy in the repair of rotator cuff tears.

The mini vent technique: a simple method to facilitate accurate secondary portal placement in shoulder arthroscopy

Accurate portal placement is crucial in diagnostic and therapeutic shoulder arthroscopy. However, knowledge of anatomy and surgical principles may not be enough. Placement of a second portal is often hindered by a small amount of bleeding. Our technique easily rectifies this frequent problem by using a simple mini-vent.

Differential arthroscopic portal placement for rotator cuff repair

We report an effective technique of arthroscopic portal placement for rotator cuff repair of the shoulder. The differential portals are placed depending on the location of the tear. After the glenohumeral arthroscopic examination, the subacromial bursoscopy is performed through the same posterior skin portal. With the rotator cuff tear in view, a spinal needle is inserted to the center of the tear, 3 cm from the lateral margin of the acromion (middle working portal). Another spinal needle is then inserted into the posterior lip of the tear, 1 cm from the lateral margin of the acromion (rear viewing portal). The rear viewing portal provides a good downward en-face view of the tear, and the middle working portal allows better access to the anterior and posterior margins of the cuff tear than the usual posterior and lateral portals do. This differential portal placement with respect to the location of the rotator cuff tear ensures superior access for arthroscopic repair of rotator cuff tears.

The 7-o'clock posteroinferior portal for shoulder arthroscopy

BACKGROUND

Access to the inferior glenohumeral joint of the shoulder is very limited through the traditional 2- or 3-o'clock anterior portals.

HYPOTHESIS

The 7-o'clock posteroinferior portal offers an excellent alternative approach.

STUDY DESIGN

Descriptive anatomic study.

METHODS

Six paired cadaveric shoulders were used to arthroscopically develop and test a 7-o'clock posteroinferior portal. The distances between the portal and the subscapular and axillary nerves were measured with the arm in six different positions, combining flexion, extension, abduction, and adduction.

RESULTS

The distance from the 7-o'clock posteroinferior portal to the axillary nerve was 39 +/- 4 mm and to the suprascapular nerve was 28 +/- 2 mm. There was no statistically significant nerve-to-portal differential distance when the arm was placed in flexion, extension, abduction, or adduction. The inside-to-outside technique produced a 7-o'clock posteroinferior portal approximately 5 mm further from both the axillary and suprascapular nerves than did the outside-to-inside method. The angle of divergence from the 7-o'clock posterior portal skin incision to the axillary nerve was 47 degrees and to the suprascapular nerve was 33 degrees.

CONCLUSIONS

The 7-o'clock portal affords safe, direct working access to the inferior capsular recess of the glenohumeral joint.

CLINICAL RELEVANCE

The 7-o'clock portal is a safe and effective technique for use by shoulder surgeons.

Complications associated with arthroscopic shoulder surgery

We review the literature on complication of arthroscopic shoulder surgery and their management. Computer data based searches were used to identify articles regarding complications of shoulder arthroscopy, as well as hand searches of Arthroscopy and Journal of Shoulder and Elbow Surgery over the last decade. Arthroscopic shoulder surgery has become a popular therapeutic and diagnostic procedure during the past two decades. As with all interventions complications can occur which require recognition and management by the orthopedic surgeon. While the literature is helpful with identifying types of complications, establishing the rate of these complications remains elusive. These complications can be divided into general complications, complications generic to all shoulder procedures, and complications specific to the type of procedure performed. General complications such as infection and anesthesia problems continue to show low incidences. Shoulder arthroscopy presents increased risk of complications over knee arthroscopy in regard to vascular and neurologic injury, fluid extravasation, stiffness, iatrogenic tendon injury, and equipment failure. New techniques of increased complexity for subacromial surgery, rotator cuff repair, and arthroscopic instability present new problems related to implant failure, nerve injury, iatrogenic fracture, and capsular necrosis. While the rate of complications especially with newer procedures remain elusive, most studies suggest that the rate is low, 5.8-9.5% in all recent review studies published. Underreporting complications makes assessment of incidence rates of complication difficult. Proper patient selection, attention to operative detail, and careful post-operative monitoring can minimize the morbidity associated with these complications.

The posterolateral portal: A new approach for shoulder arthroscopy

Since the beginning of shoulder arthroscopy, many different approaches were described for Bankart repair to allow visualization and treatment. The anterior portals do not allow access to the posterior and inferior part of the glenoid. We present a new instrumental portal for shoulder arthroscopy. This approach is perfectly safe, without any anatomic risk. It is particularly helpful in the correct treatment of an anterior Bankart lesion, in repairing posterior and inferior extensions of a Bankart lesion, and in performing a plication in multidirectional hyperlaxity.

The accessory posterior portal for shoulder arthroscopy: Description of technique and cadaveric study

As the indications for shoulder arthroscopy continue to expand, so too does the need for complete access to the glenohumeral joint. Specific regions of the joint, including the axillary recess, are often times difficult to access using traditionally described posterior and anterior portals. In this article, we describe a technique for the placement of an accessory posterior portal into the inferior hemisphere of the glenohumeral joint, effectively in the 8 o'clock or 4 o'clock position. To demonstrate the safety and effectiveness of this portal, 6 cadaveric specimens were dissected after the placement of a standard and accessory posterior portal. The proximity of the posterior portals to the axillary and suprascapular nerves was analyzed. Measurements were made in simulated beach-chair and lateral decubitus positions. The authors show that the accessory posterior portal is safe to use and may prove useful to the surgeon who wishes to gain access to the inferior recesses of the glenohumeral joint.

Arthroscopic shoulder instability surgery. Complications

Complications associated with arthroscopic shoulder stabilization are relatively common. Excluding recurrence, complications are rarely disabling. Current statistics undoubtedly underestimate the true incidence of complications. Many complications, including neurovascular injuries and articular damage, are preventable and can be minimized through familiarity with anatomy, proper surgical technique and instrumentation, and clinical experience. Nevertheless, despite these efforts, a few complications, including recurrent instability, persist. Despite careful patient selection and attention to labral pathology and capsular laxity, arthroscopic repairs continue to have success rates lower than those achieved through open means. While cautiously proceeding toward a more complete understanding of the instability continuum, surgeons must maintain a high index of suspicion for new techniques that purport to "solve" the problem of arthroscopic shoulder stabilization, lest the history of enthusiastic but ultimately unsubstantiated claims is repeated. Outcomes must withstand the rigors of scientific scrutiny and the test of time. Without this cautious vigilance, the appeal of today's solutions becomes the fodder of tomorrow's articles about the complications of arthroscopic shoulder stabilization.

Morphology of the axillary nerve in an anteroinferior shoulder arthroscopy portal

An anteroinferior portal can be safely used in arthroscopic shoulder surgery but requires an in-depth knowledge of axillary nerve anatomy. The purpose of this report is to present the qualitative and spatial anatomy of the axillary nerve and to describe patterns of arborization that may affect safe anteroinferior arthroscopic portal placement. Measurements were taken in 42 embalmed cadaveric shoulders (20 male, 22 female). The distance from the acromioclavicular (AC) joint to the axillary nerve averaged 7.90 cm (range, 7.2 to 9.1 cm) in males and 6.37 cm (range, 5.2 to 8.1 cm) in females. We describe the axillary nerve index (distance of nerve from the AC joint/length of deltoid from AC joint) which can be used to predict the location of the axillary nerve along the anterior clavicular line (ACL). The axillary nerve index averaged 0.48 (range, 0.42 to 0.57) in males and 0.41 (range, 0.31 to 0.57) in females. Four types of morphology were noted in the axillary nerve: (1) main trunk with superior and inferior branches, (2) main trunk with superior branches, (3) main trunk with inferior branches, and (4) main trunk only. Our work supports the traditional operable safe zone for the axillary nerve.

The adduction distraction maneuver

The adduction distraction maneuver is presented as an adjunct to the surgeon's technical skills to assist with the initial introduction of the shoulder arthroscope. Both novice and experienced arthroscopists can experience difficulty establishing access to the glenohumeral joint. Often this results in articular cartilage or soft tissue damage. The adduction distraction maneuver when used in the "beach chair" seated position for shoulder arthroscopy can facilitate posterior portal placement and minimize iatrogenic trauma.

Shoulder arthroscopy and nerve injury: pitfalls and prevention

Shoulder arthroscopy has become a very useful diagnostic and therapeutic modality. Unfortunately, like many other invasive procedures it can have complications. One of the most worrisome complications, for both the patient and surgeon, is that of nerve injury. Nerve injury during shoulder arthroscopy is often a transient phenomenon although a more severe injury has been documented. We review much of the literature on this subject and discuss some of the many pitfalls and preventative strategies that have been reported.

Acromial compromise with use of a transacromial portal: a biomechanical study

In an experimental evaluation with 14 paired cadaveric scapulae we found that the transacromial arthroscopy portal, used occasionally in the repair of superior labral lesions, will reduce the structural integrity of the acromion to approximately 60% (range 25% to 85%) of its original strength, thereby placing it at increased risk of fracture. These studies provide baseline biomechanical information and suggest that limited shoulder activity is indicated after use of this portal.